Hi, John-

First off it isn't really my idea - seems like it's been around for a while. I am wondering, though, if materials and techniques may have changed over the years in a way that might it worth reconsidering. Also, I don't think I'm actually going to try it myself - I'm better off just sticking with a tried and true strip design.

As to your questions, I'm roughly the opposite of an expert on foam - I've just read a few product descriptions and FAQs - but it seems like there are a number of different products with various properties, so anyone attempting this would have to do the research to find the right configuration for the job. I'm not looking at this as "I've got a sheet of foam in my garage, how do I make it work?" but rather starting with the requirements that would result in this approach making sense, and then investigating whether or not such a product actually exists.

I think the ideal foam would let you use wide strips, ideally single pieces between the wood stringers, with enough flexibility so that it will conform to the underlying forms with minimal pressure - maybe using tape to hold it in place, maybe laminating together two thin layers to achieve the flexibility. It would accept glue, so that you could attach it to the stringers, and you'd be able to hand-laminate it, it would require less sanding and finishing than the cedar equivalent plus would be lighter but sufficiently strong.

Does such a product exist? I don't know. Everything I find on the various forums suggests "don't bother using foam, just use plywood." But I don't think plywood is actually an option here, is it? But really the same question would apply - say you wanted to build a Night Heron or the equivalent, but (for whatever reason) you planned to paint the hull. I know you can get the hybrid version with the S&G plywood hull, but what if you wanted the lines and performance of the strip version - could you build it in plywood on the strip forms? It's the same scenario, really, nothing special about foam per se.